I'm trying this project so far I've got the schematic of a Pro Micro, which is powered through GPIO from a Raspberry Pi Zero, and want to remove the micro usb connection and able to flash it using an avr programer and a few pins.
How do I get to Achieve that? also the Pro Micro is getting D+/D- from the the raspberry's D+/D- pads as well. Schematic below for reference.